This invention relates to escape sash release mechanisms, especially in connection with a large vehicle window which serves as an emergency escape, and more particularly side windows in buses, trains, or the like.
It is common practice for large vehicles used in passenger service to provide the side windows as emergency escapes. With such an arrangement, at least one window sash on each side of the vehicle is an escape sash which is hinged or otherwise pivotally mounted at one of its edges so it can be swung out of the window opening to provide an emergency exit. The unhinged or free side of the sash is maintained closed and weathertight by a relatively uncomplicated latch mechanism. In modern buses and passenger trains the windows are rather elongated, and extend alongside several rows of seats. In that case, instead of a single latch mechanism, several latches are employed along the sash to hold the window closed and weathertight but without buckling. A sash bar generally extends along the inside of the sash on the latch side of the window and is connected to each of the latch mechanism releases, so that in the event of an emergency a passenger can, by simply raising the sash bar, unlatch all the latch mechanisms to open the window.
A number of escape sash release mechanisms have been proposed, for example as discussed in U.S. Pat. Nos. 2,830,843; 3,942,286; 3,431,677; 2,015,448; 3,913,265; and 4,313,280.
The latch arrangement of U.S. Pat. No. 4,313,280 has a keeper bar mounted on a fixed part of the sash and a latch and release bar hinged to the swingable part of the sash frame. There, the keeper bar is formed with a keeper flange that is an elongated bead of cylindrical configuration that snap fits into a similarly contoured socket formed in the sash release bar. Generally, both the keeper and the sash release bar are of extruded aluminum. The keeper contacts a flange of the sash bar, but not the hinge member, which is affixed to the sash. This arrangement tends to loosen over time due to wear, and noticeable rattling, with some air leakage, often occurs.